I've noticed over the last couple of weeks that the mouse cursor (ie, I-beam cursor) flickers or even disappears temporarily when I move it across the editor. It's a minor issue, but gets a bit annoying over time. I don't notice similar flickering in other text editors, like TextEdit, Nisus Writer, or Scrivener.

And in case anyone asks, this is different from the usual ghost artifacts one might see on an LCD as it redraws a quickly moving object like the mouse pointer. The i-beam actually vanishes or flickers noticeably (even when moving relatively slowly) across just the editor. The i-beam behaves as I would expect when I move it around the Notes panel or the Document browser.

Thanks for the response. I'll notice this behavior even when the CPU usage isn't any higher than 2% or 4%, and the data read/written to the HD is under 10 KB/sec (according to Activity Monitor), so there are definitely no TM, spotlight indexing, or other HDD intensive operations underway.

I work mostly on my portable computer—an early 2011 MacBook Pro with a 2.2 GHz Core i7 and 8 GB of RAM—so I just checked to see if Ulysses on my late 2009 27" iMac does the same thing. It doesn't, or, at least, I don't notice it. I'm not sure why Ulysses on the portable should show this noticeable lag in redrawing the mouse cursor when it passes over the editor. Perhaps it is related to the graphics card? The portable has an AMD Radeon HD 6750M and a built-in Intel HD Graphics 3000—the latter is use right now according to the system report. Whereas the desktop just has the ATI Radeon HD 4850 and no built-in Intel graphics chip.

Also, the mouse cursor only displays this behavior when Ulysses is in the foreground. If the Ulysses window is still visible, but the Finder, for example, is in focus, the mouse cursor remains an arrow pointer (as I would expect), never turns into the i-beam, and doesn't noticeably flicker.

I just realized I could switch to the high performance graphics card (ie, the AMD Radeon) by unchecking "Automatic graphics switching" in the "Energy Saver" control panel. When I do this, the i-beam stops flickering in the Ulysses editor window.

I guess this is a temporary fix that's feasible while the computer is plugged in, but it probably wouldn't be very good for my computer's battery life.